[Modification and application of recombinant yeast bioassay for measuring the AhR ligand activity]

A recombinant yeast bioassay, a yeast Saccharomyces cerevisiae, in which the human AhR and ARNT complex are coexpressed, is one of the methods to screen the active AhR agonist. In this study, the original agonist test was modified. The exposure time was reduced from 18 to 8 hours when experiment was under the following conditions: (1) the yeast was cultured in 0.2% glucose medium for 24 hours; (2) chemical exposure was carried in 2% galactose medium in glass tube. Finally, the AhR acitivity of hexachlorobenzene and pentachlorobenzene were assessed, and their toxicity equivalent factors were found to be 0.018629 and 0.000294, respectively.